Transcript Pneumonia

By
Professor Of Pediatrics,
Head of Allergy & Clinical
Immunology Unit - Mansoura
University
Egypt
Out Line
(1) Definition and Pathophysiolgoy of
pneumomnia
(2) Does the patient have a pneumonia?
(3) What is the microbial etiology?
(4) Where you treat?
(5) How to treat?
Definition
It’s an infection in alveolar spaces
(pulmonary parenchyma) leading to their
Consolidation.
Consolidation means the alveoli are
filled with exudates and inflammatory
cells with loss of their gaseous content.
Pathophysiology
A- Development of Pneumonia:
• Virulent organism.
• Immune compromised host
Local
Systemic
B- Pulmonary host defenses
(1)Mechanical and structural:
 Cough.
 Mucocilliary clearance
 Airway branching (configuration)
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Pathophysiology
Pulmonary host defenses
(2) Cellular defenses:
 Resident alveolar macrophages
 Recruited Neutrophils occures when
alveolar macrophages are over
whelmed in lower respiratory tract
infections.
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Pathophysiology
(3)Humoral defenses
 IgA in upper airway
 IgG in lower airway
(4) Inflammatory and molecular
defenses:
 Airway epithelium through secretion of
peptides called defensins, and chemokines.
 Cytokines as: IL-10,GM- CSF.
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Pathophysiology

Bacteria or virus gain access to respiratory
tract from:
1. Inhalation of contaminated air
2. Microaspiration
3. Hematogenous seeding of the lung.

Whether Pneumonia is the result of such
bacterial entry depends on interaction between
the bacterium (load, Virulence) and pulmonary
defense mechanism.
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Pathophysiology

The usual out come is ingestion of bacteria or
virus by alveolar macrophages, an alternative but less
common is complement mediated bacterial lyses

When these mechanisms don’t destroy alveolar
bacteria,polymorph nuclear leukocytes with their
phagocytic capability are required with the result
inflammatory response
results in Pneumonia
passing in 3 stages.
Pathology of Pneumonia:
1- Stage of congestion: (red hepatization)
Due to antigen antibody reaction no
radiological findings.
2- Stage of gray hepatiztion:
Respiratory distress and homogenous
opacity in chest rdiography.
3- Stage of resolution:
When immune system takes upper
hand, resolution and convalescence.
Pathology
Classification of Pneumonia:


Two types: typical And atypical.
(1) Typical pneumonia
(2) Atypical pneumonia
Another Classification:
(1) Community- acquired pneumonia ( CAP)
(2) hospital – acquired pneumonia ( nosocomial
pneumonia)
Out Line
(1) Definition and Pathophysiolgoy of pneumomnia
(2) Does the patient have a pneumonia?
(3) What is the microbial etiology?
(4) Where you treat?
(5) How to treat?
Clinical and Radiological Diagnosis
of Pneumonia
(1) Respiratory distress
(2) Bronchial breathing or fine
consonating creptation by
auscultation
(3) Homogenous opacity is a cardinal
radiological sign
Clinical and Radiological Diagnosis
of Pneumonia

To differentiate between Bacterial and viral
etiology
Look for:
- preceding symptoms
- Fever
- Para pneumonic effusion
- Wheezes
- Distribution & size of homogenous
opacity
Radiology
Radiology
Out Line
(1) Definition and Pathophysiolgoy of pneumomnia
(2) Does the patient have a pneumonia?
(3) What is the microbial etiology?
(4) Where you treat?
(5) How to treat?
Etiological Diagnosis

It is difficult to determine the causative
organism of Pneumonia. So the treatment
usually empirical based on Predicting factors
for the causative organism as the following.
a) Age of the patient.
b) Immune status,
c) Extra pulmonary manifestations.
* It can be confirmed by:
Culture + Specific tests.
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Etiological Diagnosis
Age as a predictor for eteological diagnosis
A- In CAP:
 Neonates:
Common:- = Group B B- hemolytic streptococci
= Gram negative enteric bacilli such as
Escherichia coli and Klepsella pneumoniae
Less frequent:
Staph-auras
P.aeruginosa
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Etiological Diagnosis
Children Past neonatal period
1- 5 month age
Chlamydia trachomatis
 > 5 years: Atypical (intracellular) micro-organisms as
mycoplasma pneumoniae, legonella, chlamydia SPP are the
commonest etiological agents.
All ages
Frequent S. pneumoniae
Infrequent causes as:
- H. influenza (vaccine)
- S, aureus but it needs special consideration for
rapid progression of the disease.
- Group A B hemolytic streptococci are uncommon
cause of pneumonia
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Etiological Diagnosis
In hospital acquired pneumonia
Common:


Gram negative organism such as:
K. pneumonia, Pseudomonas aurugnosia and
serrata spaces
Gram positive organisms such as:
S. Aureus most frequent leogionella pneumoniae
is rare
Investigation of Pneumonia
Routine Investigation:




X ray
CBC with differential
SaO2,
Blood culture
Specific Investigation:
Bronchoscopy and C.T for unresolved
pneumonia
 Serology ( IgM, IgE, IgG)
 Sputum and pleural evaluation

Out Line
(1) Definition and Pathophysiolgoy of pneumomnia
(2) Does the patient have a pneumonia?
(3) What is the microbial etiology?
(4) Where you treat?
(5) How to treat?
Indication for Hospitalization in
Pneumonia
1) Patients with tacchypnea, toxic
appearance, poor feeding , dehyration
2) Infant < 2 months of age
3) Massive para pneumonic affusion
4) Associated co-morbidty
5) Immundeficiency.
Staphylococcal Pneumonia

It is an infrequent cause of pneumonia
 Age under one year , it occurs either community
acquired following influenza or at nosocomial setting
Characters:-
1) At the onset, chest radiographs may be normal
However. S. aureus pneumonia is more
commonly bronchopneumonia with a patchy
central infiltrate. Usually unilateral
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Staphylococcal Pneumonia
2) Rapid progression of the disease from
Patchy cansolidation to cavity, pneumatocele or
tension pneumothorax should raise the
possibility of S. aureus pneumonia, when it occurs
3) Effusion or empyema
Develops in about 90% of patients
 Spontaneous pneumothorax or pyopneumothorax
Occur in about 25-50% of cases
 Pneumatocele
Occur in > 50% of cases and may change hourly in
number or size in acute phase.
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Staphylococcal Pneumonia
This previous radiographic picture of S. aureus pneumonia
is not pathognomonic as it occurs with:
 Pneumonia caused by:
Klebsiella species, other gram negative bacteria group
A streptococci and occasionally pneumococci
OR it may mimic congenital diaphragmatic hernia.
4) Staphylococcal pneumenia
It should be suspected in hospitalized infants (particularly those
in ICU) who develop parenchymal unexplained opaque shadows.
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Staphylococcal Pneumonia
5) Species of staphylococci
A) S. aureus
coagulase positive
B) S. albus
C) Staphylococcus epidermidis → coagulase
negative
 Morphologically all staphylococci are gram
positive
 Coagulase does not reflect virulence
 Virulence of S. aureus related to secretion of
different toxins as hemolysins and leukocidin
that kills neutrophils.
Treatment of Staphylococcal
pneumonia
The production of B- lactamase by nearly all S. aureus
isolates rendered ineffective any drug bydrolysed by this
enzyme.
 First – line therapy is: Hospital admission,
B lactamase resistant penicillin
such as Methicillin → no longer in use
its modern analogs i.e oxacillin, cloxacillin,
Flucloxacillin, nafcillin
MRSA ( methicillin resistant S. aureus) which was
found to be resistant to all B lactams and all
cephalosporin compounds.
Treatment of Staphylococcal
Pneumonia
 MRSA infections: that are nosocomially
acquired was found to be sensitive to
Vancomycin
 Now MRSA infection became community
acquired
 Clindamycin: indicated in MRSA infection in
patients allergic to B-lactams
 Duration of treatment: 2-3 weeks, but 6 weeks
recommended to decrease the risk of relapse
 Supportive therapy: o2, maintenance of, fluid,
electrolyte and hemoglobin levels
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Treatment of Staphylococcal
Pneumonia
 The most important complication is
Empyema and lung abscess, pneumothorax each
has a special treatment
Treatment in summary
 B. lactamase – resistant penicillins or first
generation cephalosporin for 2-3 weeks
MRSA → vancomycin
Clindamycin
MRSA
patient allergic to B lactams
HaemophilusInfluenzaType b




H. influenza is gram - negative bacilli
H. influenza : can lead to invasive infectious in
pediatrics as pneumonia, meningitis, cellulites,
epiglottites, septic arthritis, osteomyelitis
percarditis and bacteremia
Incidance of H. influenza pneumonia decrease
after administration of Hib canjugate vaccine
The virulence of serotype b is related to serotype
b capsular polysaccharide
Haemophilus Influenza Type b

Radiographic findings of H. influenza
pneumonia vary from:1) Bronchiolctic type with central linear
infiltrates and over inflation
2)Bronchopneumonia with patchy
consolidation with no lobar affection
Treatment of H. Influenza
Pneumonia
we have two clinical situations:
1) pneumonia complicated with bacteremia,
pleural effusion usually occur in children less
than 12 months. Those group needs Hospital
admission with I.V treatment for 7-10 days
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Treatment of H. Influenza
Pneumonia
2) Pneumonia and the patient is not appears
severely ill those group treated at home with
oral antimicrobial

Oral therapy in mild H. influenza infection
TMP/ SMX or amoxicillin / clavulanate
Erythromycin has poor activity

Invasive infections: IV treatment by
cephalosporin (cefotaxime or ceftriaxone)
Alternatively chloramphencol with ampicillin,
Mycoplasma Pneumonia

Mycoplasma pneumoniae causes:
Non classic bacterial pneumonias. They are
small organisms that are able to live outside the
host cell. Because they have no cell wall, they
are not killed by cell wall- active agents such as
penicillins and cephalosporins.

Mycoplasma pneumonia is common cause
of CAP that occurs > 5 years of age
Pathogenesis of Pulmonary Infections
Infection with M. pneumoniae are acquired via
respiratory route from droplet infection.
The organism attaches to a receptor on respiratory
epithelium and remains extra cellular causing
cellular damage.
Specific cell mediated immune responses increase
with age so it tends to be milder in children than
in adults and also severe in reinfection.
Diagnosis of Mycoplasma Pneumonia
The diagnostic clue: Is the poor correlation
between clinical symptoms which are severe,
with minimal pulmonary physical and
radiological findings. This poor correlation
present all through the course of the disease and
this is the hall mark of diagnosis of M.pneumonia.
Clinical Picture
1.
2.
Typically the patients present with gradual onset of
malaise, headache and fever over 1 week. Cough dry or
productive associated with symptoms as vomiting, diarrhea,
chest pain, sore throat.
Physical findings are relatively minimal early in the
course of illness no finding on chest examination later on
bronchial breathing crackles or wheezes can be heard.
3- Radiologic findings:

Usually unilateral in 87% and involves lower lobes

In the early stages the pattern is reticular and interstitial

Later patchy or segmental areas of consolidation are
noted.
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Clinical Picture
4- Extra pulmonary manifestation:
 They are the second hallmark of M. pneumonia.
 Such complications commonly occur 1-21 days after the
onset of respiratory symptoms. Most of the diagnosis have
been based on the result of serology (four fold rise in
complement fixation titres) rather than no culture
confirmation.
Neurological manifestations.
 Dermatologic manifestations.
 Cardiac manifestations.

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Clinical Picture
4- Extra pulmonary manifestation:
GIT manifestations.
 Hematologic manifestations.
 Musculoskeletal manifestations.
 Genitourinary manifestations.
 Immunologic manifestations.

Diagnostic Criteria of Mycoplasma
Infection
Serologic assays are the mainstay for diagnosing mycoplasma
infection:1.Cold agglutinin identification
Cold agglutinins usually appear by the end of first
week and disappear by 2-3 months
Cold agglutinin responses are non specific and
consistent mostly IgM
So IgM lacks specificity and sensitivity
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Diagnostic Criteria of Mycoplasma
Infection
Specific serological test:


Complement fixation test has been used as
standared for diagnosis with titer > 1:32
The test measures IgM antibodies
This test has 90% sensitivity and 94%
specificity
Polymerase chain Reaction(PCR)
PCR diagnosis M. pneumonia in both throat swab and
CSF.
Treatment of M. Pneumonia

Macrolides are the drug of choice as:Erythromycins, Azithromycin are specific
treatment.

Because M. pneumonia has no cell wall, it is
resistant to penicillins, cephalosporins and
other cell wall active agents.
Pneumococcal Pneumonia
Pneumococcus (Streptococcus Pneumoniae)
It is the most common cause of bacterial
pneumonia in children. The organism is
gram positive cocci.The virulence of the
pneumococci is related to there capsule.
It affects all ages.
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Pneumococcal Pneumonia
Diagnosis:
1) It is typical pneumonia with sudden onset
of fever, cough, chest pain and dyspnea.
2) Physical examination:
• Pleurtic chest pain my be referred to
abdomen with misleading suspicion of acute
appendicitis.
• Symptoms and signs of meningismus may
be present with upper lobe pneumonia.
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Pneumococcal Pneumonia
2) Physical examination:
• Dullness on percussion denotes empyema because the
lesion usually patchy in distribution
• Fine rales difficult to be heard.
Pneumococcal Pneumonia
Treatment:
1) Penicillins are the drugs of choice in treatment of
pneumococcal infection.
2) If the patient is resistant to penicillins,
cephalosporin is indicated.
3) If the patient is allergic to penicillins: vancomycin
clindamycin or chloramphenecol are the drugs of
choice .
Recurrent or Unresolved Pneumonia
I- Multiple lobe affection:
- Congential heart disease with excess pulmonary blood
flow.
- Immune deficiency either local or general.
- Specific infection as T.B and fungal infection
(Aspergillus)
II- Singal lobe affection:
- Obstruction : Intraluminal, Extraluminal.
- Structural abnormalities as pulmonary
sequestration.
Differential Diagnosis of
Pneumonias
1) Between 4 common types of pneumonia:




Staph pneumonia
Mycoplasma Pneumonia
H. influenza pneumonia
Pneumococcal pneumonia
2) From other causes of:
 Respiratory distress
 Pulmonory inflitrates.